What Makes an Online Converter Reliable for Everyday Use?

Hello everyone.

I frequently need to convert files, units, or media formats for work and personal projects, but there are so many tools available that it is difficult to know which ones are trustworthy.

Some are fast, while others have limitations or require registration. Recently, I started exploring different online converter options and noticed significant differences in speed, accuracy, supported formats, and privacy policies.

What features do you consider most important when choosing a converter? Do you prefer free tools, or are paid services worth the investment?

I would appreciate recommendations based on your real experiences and daily usage.